Edited by David A. Weitz, Harvard University, Cambridge, MA, and approved December 24, 2018 (received for review October 23, 2018)
It is always a challenge to see the deposition of single PM2.5 particles, the harmful inhalable aerosols in the polluted air, in alveolar region, and their invasion to the extrapulmonary organs. The dynamic deposition process and the nonuniform deposition pattern of PM2.5 in the alveolar region are revealed using a fluorescent imaging method with high temporal and spatial resolutions. This observation technology would also bring insight in the study of the public health in air pollution and lung administration.
The deposition of PM2.5 (fine particulate matter in air with diameter smaller than 2.5 μm) in lungs is harmful to human health. However, real-time observation on the deposition of particles in the acinar area of the lung is still a challenge in experiments. Here, a fluorescent imaging method is developed to visualize the deposition process with a high temporal and spatial resolution. The observations reveal that the deposition pattern is nonuniform, and the maximum deposition rate in the acinar area differs significantly from the prediction of the widely used average deposition model. The method is also used to find single particles in the kidney and liver, though such particles are commonly believed to be too large to enter the extrapulmonary organs.
Author contributions: J.L. and H.C. designed research; D.L. performed research; H.C. contributed new reagents/analytic tools; Y.L., G.L., Y.Z., and H.C. analyzed data; and J.L. and H.C. wrote the paper.
The authors declare no conflict of interest.
This article is a PNAS Direct Submission.
This article contains supporting information online at www.pnas.org/lookup/suppl/doi:10.1073/pnas.1818134116/-/DCSupplemental.
Published under the PNAS license.
